Curable mixtures

ABSTRACT

The invention relates to curable mixtures which contain 1,10-substituted 1,10-diaminodecanes, as the curing agents, new 1,10-substituted 1,10-diaminodecanes and a process for the manufacture of the latter. 
     The new 1,10-diaminodecanes are manufactured by catalytic hydrogenation of corresponding 3,12-substituted 1,2-diazo-1,5,9-cyclododecatrienes in the presence of an inert organic solvent, while raising the temperature to at least 120° C.

The present invention relates to curable mixtures which contain1,10-substituted 1,10-diaminodecanes as the curing agents, new,substituted 1,10-diaminodecanes and a process for their manufacture.

The curable mixtures according to the invention are suitable for themanufacture of mouldings, impregnated materials, coatings, lacquers andsealings and are characterised in that they contain (a) a polyepoxideand (b), as the curing agent, at least one 1,10-diaminodecane of theformula I ##STR1## wherein R₁ and R₃ independently of one anotherrepresent an unsubstituted or substituted alkyl, cycloalkyl, aralkyl,phenyl or naphthyl group and R₂ and R₄ independently of one anotherrepresent hydrogen or an unsubstituted or substituted alkyl, cycloalkyl,aralkyl, phenyl or naphthyl group or R₁ and R₂ and/or R₃ and R₄,conjointly with the carbon atom to which they are linked, form anunsubstituted or substituted 5-membered to 12-membered alkylene oroxaalkylene ring.

In principle, any desired groups which cannot be hydrogenated under thereaction conditions, such as alkyl, alkoxy, alkylamino,N,N-dialkylamino, cyclic ether and cycloalkyl groups, are possible assubstituents on alkyl, cycloalkyl, aralkyl, phenyl and naphthyl groupsrepresented by R₁ to R₄.

Possible alkyl groups R₁ to R₄ are above all straight-chain or branchedgroups having 1-18, preferably 1-8, carbon atoms. If such groups aresubstituted, they are, for example, alkoxy, alkylamino orN,N-dialkylamino groups having in each case 1-4, particularly 1 or 2,carbon atoms in the alkoxy or alkyl portions, cyclic ether groups having3 or 4 carbon atoms, or cycloalkyl groups having 5-8, preferably 5 or 6,ring carbon atoms. The following should be mentioned as examples ofalkyl groups R₁ to R₄ of this kind: methyl, ethyl, n-propyl, isopropyl,n-, sec.- and tert.-butyl, n-hexyl, n-heptyl, n-octyl, n-decyl,n-dodecyl, n-octadecyl, methoxyethyl, 2-ethoxyethyl, 2-methylaminoethyl,3-N,N-diethylaminopropyl, 2-cyclohexylethyl, 2-furyl-(3)-ethyl and3-pyranyl-(3)-propyl.

If cycloalkyl, aralkyl, phenyl or naphthyl groups represented by R₁ toR₄ are substituted, possible substituents are above all alkyl, alkoxy,alkylamino and N,N-dialkylamino groups having in each case 1-4,particularly 1 or 2, carbon atoms in the alkyl or alkoxy portions.

Cycloalkyl groups represented by R₁ to R₄ can be 1-nuclear or 2-nuclearand preferably have 5-12, particularly 5- 10, ring carbon atoms.

The following examples should be mentioned: the cyclopentyl,2-propylcyclopentyl, cyclohexyl, 4-methylcyclohexyl,4-methoxycyclohexyl, 4-N,N-diethylaminocyclohexyl, cis- ortrans-decahydronaphthyl, methylcycloheptyl, cyclooctyl and cyclododecylgroups.

Aralkyl groups represented by R₁ to R₄ preferably have 6-10 ring carbonatoms. Examples of such groups are: the benzyl, 2-phenylethyl,1-methylnaphthyl, 4-methoxy and 4-methylbenzyl groups.

The following should be mentioned as examples of phenyl and naphthylgroups R₁ to R₄ according to the definition: the phenyl, 1-naphthyl,2-naphthyl, 4-ethylphenyl, 3-methoxyphenyl, 4-n-propylaminophenyl,3,4-dimethoxyphenyl and the 4-N,N-dimethylaminophenyl groups.

Alkylene or oxaalkylene rings which are formed by R₁ conjointly with R₂and/or R₃ conjointly with R₄, can also be substituted, for example byalkyl or alkoxy groups having 1-4, particularly 1 or 2, carbon atoms.Thus R₁ and R₂ or R₃ and R₄ form, conjointly with the carbon atom towhich they are linked, for example, a cyclopentyl, cyclohexyl,methylcyclohexyl, tetrahydrofuryl, 4-methyltetrahydrofuryl-3,tetrahydropyranyl, cycloheptyl, cyclooctyl, cyclodecyl or cyclododecylring.

Preferred 1,10-diaminodecanes are those of the formula I wherein R₁ andR₃ independently of one another represent an unsubstituted alkyl grouphaving 1-18, particularly 1-8, carbon atoms, a 1-nuclear or 2-nuclearcycloalkyl group having 5-10 ring carbon atoms, which can be substitutedby alkoxy, alkylamino or N,N-dialkylamino groups having in each case 1or 2 carbon atoms in the alkoxy or alkyl portions, the benzyl or2-phenylethyl group, an unsubstituted phenyl group or a phenyl groupwhich is substituted by alkyl, alkoxy, alkylamino or N,N-dialkylaminogroups having in each case 1 or 2 carbon atoms in the alkyl or alkoxyportions, or an unsubstituted naphthyl group, and R₂ and R₄independently of one another represent hydrogen or one of the groupsindicated above under R₁ and R₃, as well as compounds of the formula Iwherein R₁ and R₂ and/or R₃ and R₄, conjointly with the carbon atom towhich they are linked, form an unsubstituted 5-membered to 12-memberedalkylene ring or an unsubstituted 5-membered or 6-membered oxaalkylenering.

In accordance with a further preference, R₁ and R₃ as well as R₂ and R₄each represent identical groups.

1,10-Diaminodecanes which are very particularly prefrred are those ofthe formula I wherein R₁ and R₃ are identical and each represent anunsubstituted alkyl group having 1-8 carbon atoms or a 1-nuclear or2-nuclear cycloalkyl group which has 5-10 ring carbon atoms, preferablycyclohexyl, cyclopentyl or cyclooctyl, and which is unsubstituted orsubstituted by alkoxy, alkylamino or N,N-dialkylamino groups having ineach case 1 or 2 carbon atoms in the alkoxy or alkyl portions, and R₂and R₄ are different and each represent hydrogen or an unsubstitutedalkyl group having 1-8 carbon atoms.

The invention also relates to the new 1,10-diaminodecanes of the formualIa ##STR2## wherein R₁ represents an unsubstituted or substituted alkyl,cycloalkyl, aralkyl, phenyl or naphthyl group, R₃ ' represents anunsubstitued or substituted alkyl, cycloalkyl, aralkyl or naphthyl groupwhich corresponds to R₃, or represents a substituted phenyl group and R₂and R₄ independently of one another represent hydrogen or anunsubstituted or substituted alkyl, cycloalkyl, aralkyl, phenyl ornaphthyl group, or R₁ and R₂ and/or R₃ ' and R₄, conjointly with thecarbon atom to which they are linked, form an unsubstituted orsubstituted 5-membered to 12-membered alkylene or oxaalkylene ring.

In the above formula Ia, what has been said in the preceding textapplies to R₁, R₂ and R₄ and to R₃ ' as an alkyl, cycloalkyl, aralkyl ornaphthyl group which corresponds to R₃, and to alkylene or oxaalkylenerings which are formed by R₃ ' conjointly with R₄.

If R₃ ' represents a substituted phenyl group, possible substituents arethose mentioned above, particularly alkyl, alkoxy, alkylamino andN,N-dialkylamino groups having 1 or 2 carbon atoms in the alkyl oralkoxy portions.

The 1,10-diaminodecanes of the formula Ia according to the invention canbe obtained by hydrogenating a compound of the formula II ##STR3##wherein what has been indicated under formula Ia applies to R₁,R₂, R₃ 'and R₄, in the presence of an inert organic solvent, by catalytic means,in one or two stages and with the reaction temperature being raised toat least 120° C, to give a compound of the formula Ia.

In the course thereof, it is also possible, depending on the nature ofthe starting compound of the formula II, of the catalyst and/or of thereaction conditions, to hydrogenate phenyl groups or naphthyl groupswhich are represented by R₁,R₂, R₃ ' and R₄ in formula II.

In the two-stage hydrogenation it is appropriate to proceed byhydrogenating a compound of the formula II at a temperature below 150° Cto give a compound of the formula III ##STR4## in the first stage, andsubsequently to hydrogenate the compound of the formula III at elevatedtemperature and preferably with the addition of ammonia, to give acompound of the formula Ia.

1,10-Diaminodecanes of the formula Ia wherein R₂ and R₄ each representhydrogen, can also be obtained by one-stage hydrogenation ofcorresponding starting compounds of the formula II at a temperature ofat least 120° C.

Hydrogenation catalysts which are in themselves known can be used as thecatalysts. These catalysts can be used in the customary forms, forexample as finely divided powders, in colloidal form, as oxides orhydroxides or applied to suitable supporting materials, such asasbestos, pumice, kieselguhr, silica gel, silica, active charcoal orsulphates, carbonates or oxides of the metals of the II to VII group ofthe periodic system, particularly magnesium, calcium, barium, zinc,aluminum, iron and chromium.

For the one-stage hydrogenation and in the first phase of the two-stagehydrogenation, it is appropriate to use noble metal catalysts, such asplatinum, rhodium, palladium, ruthenium and iridium catalysts,preferably rhodium/aluminium oxide or palladium-on-charcoal catalysts.

For the second phase in the two-stage hydrogenation, it is preferable touse finely divided cobalt and, particularly, finely divided nickel(Raney cobalt or Raney nickel).

It is not necessary to isolate intermediately the compounds of theformula III. On the other hand, it is advisable to remove the catalystsused in the first stage before a further reaction is carried out, forexample by filtration, if necessary using filter aids, such as silicagel.

Tert.-butanol, ethylene glycol monomethyl and monoethyl ethers, n-hexaneand cyclohexane should be mentioned as examples of inert organicsolvents which are suitable for carrying out the hydrogenation accordingto the invention.

The hydrogenation reactions are generally carried out in a closed systemand - at least in the final stage - under pressure.

Depending on the nature of the compounds of the formula II and/or thecatalysts employed, the reaction temperatures can vary within wideimits. In the one-stage process they are generally between 120° and 220°C, preferably between about 140° and 180° C.

In the two-stage hydrogenation the reaction temperatures during thefirst phase are appropriately between about 20° and 130° C and aresubsequently raised to about 170° to 220° C.

After the completion of the reaction the catalysts and the solvent areremoved in a customary manner.

The substituted 1,10-diaminodecanes according to the invention aregenerally obtained as mixtures of diastereomers in the form ofcolourless oils and can be isolated and purified in a manner which is initself known.

The starting compounds of the formula II are known or can bemanufactured in a manner which is in itself known, by reacting 1,3-butadiene with an azine of the formula ##STR5## at temperatures of up to100° C, preferably at 70°-95° C, in the presence of a catalyst which isobtained under reducing conditions by the action of an electron donor oncarbon monoxide-free compounds of nickel. It is preferably here toemploy catalysts which are obtained by reducing a carbon monoxide-freecompound of nickel by means of halogen-free metal alkyls or metal arylsin the presence of electron donors, for example a catalyst which isobtained by reducing nickel acetylacetonate by means ofethoxy-diethyl-aluminium in the presence of triphenylphosphine.

The manufacture of some 1,10-diaminodecanes according to the inventionis described in the following examples.

A. PREPARATIVE EXAMPLES Example 1 (a)3,12-Dicyclohexyl-1,2-diaza-1,5,9-cyclododecatriene ##STR6##

8.8 g (0.034 mol) of nickel acetylacetonate and 8.8 g (0.033 mol) oftriphenylphosphine are dissolved in 500 ml of absolute toluene. Approx.20 g of 1,3-butadiene are introduced into the clear, green solution atroom temperature (20°-25° C). Reduction is then carried out at roomtemperature by means of 14 ml (0.09 mol) of ethoxydiethyl-aluminum, thecolor of the solution changing from green to orange-red. The mixture isnow warmed as quickly as possible to 80° C, while passing in a steadystream of 1,3-butadiene. 991 g (4.5 mols) of cyclohexylaldazine,dissolved in 1.6 l of absolute toluene, are then added dropwise in sucha way that, on the one hand the exothermic reaction which now sets indoes not rise above 90°-95° C (cooling) and, on the other hand,butadiene is always present in excess in the reaction solution. After adropwise addition time of 50 minutes, the mixture is subsequentlystirred for a further 15 minutes and part of the toluene (approx. 1 l)is then distilled off under a slight waterpump vacuum using a descendingcondenser.

After cooling to 20°-25° C, 3 l of isopropanol are added and the mixtureis cooled to 0° C. A diastereomeric mixture of3,12-dicyclohexyl-1,2-diaza-1,5,9-cyclododecatriene is precipitated inthe form of colourless crystals; these are filtered off, washed with alittle cold methanol and then dried over phosphorus pentoxide in avacuum drying cabinet at room temperature. 973.5 g of reaction productare obtained. The mother liquor is now evaporated and 1.8 l of acetoneare added to the resulting green syrup. A further 260 g of3,12-dicyclohexyl-1,2-diaza-1,5,9-cyclododecatriene are precipitated.

The total yield therefore amounts of 1,233.5 g = 91.1% theory, relativeto cyclohexylaldazine employed (mixture of diastereomers); melting point102°-3° C.

Analysis for C₂₂ H₃₆ N₂ (molecular weight 328.5): Calculated; C, 80.42%;H, 11.04%; N, 8.53% Found: C, 80.44%; H, 10.96%; N, 8.53%.

(b) 1,10-Dicyclohexyl-1,10-diaminodecane ##STR7##

328.5 g (1 mol) of 3,12-dicyclohexyl-1,2-diaza-1,5,9-cyclododecatrieneare dissolved in 2.6 l of pure tert.-butanol and the mixture is slowlyheated to 180°-200° C in a stirred autoclave (temperature increaseapprox. 30° C per hour). 33 g of a rhodium-aluminium oxide catalyst (5%by weight of Rh) are added at this temperature and the mixture ishydrogenated for 8 hours (initial pressure 120 bars). At the end of thistime the autoclave is cooled to room temperature (20°-25° C). Thecatalyst is filtered off through kieselguhr and rinsed with 100 ml oftert.-butanol. The solvent is then evaporated in a rotary evaporator at12 mm Hg. Residual solvent is then removed in a high vacuum at a bathtemperature of 60° C. This gives 320 g of a colourless, oily residue.The reaction product is purified via the corresponding bis-hydrochoride,by dissolving the residue in 1.8 l of anhydrous diethyl ether andcooling the resulting solution to 0°-5° C, after which hydrogen chlorideis passed in until the ether solution is saturated. A colourless,crystalline precipitate is formed which is filtered off, rinsed withdiethyl ether and dried in the air. This precipitate is dissolved inwater and the pH of the solution is adjusted to at least 14 by means ofconcentrated sodium hydroxide solution. The aqueous phase is extractedwith diethyl ether and the ethereal solution is washed with water anddried over MgSO₄. The diethyl ether is evaporated off in a rotaryevaporator and the residue is distilled through a short Vigreux columnin a high vacuum. This gives 304 g (0.904 mol) of colourless1,10-dicyclohexyl-1,10-diaminodecane; boiling point 190°-193° C/0.05 mmHg; yield: 90.4% of theory, relative to3,12-dicylohexyl-1,2-diaza-1,5,9-cyclododecatriene reacted; n_(D) ²⁰ :1.4944.

Gas chromatogram: Signal at 97.3% and 1.7% (mixture of diastereomers).

Analysis for: C₂₂ H₄₄ N₂ (molecular weight 336.58): Calculated C,78.45%; H, 13.20%; N, 8.35%; Found C, 78.8%; H, 13.40%; N, 8.2 %.

Mass spectrogram: molecule peak 336; fragment masses 253, 236, 154 and112.

H¹ -NMR spectrum (100 Megahertz [MHz]): δ [ppm] = 2.4 (multiplet), 1.7(multiplet), 1.3 (multiplet), 1.1 (multiplet), 1.0 (singlet) in theratio of 2:38:4.

For further characterisation, 1.1 g of1,10-dicyclohexyl-1,10-diaminodecane are boiled under reflux in 4 ml ofacetic anhydride for 10 minutes. After cooling the reaction mixture to20°-25° C, colourless crystals are precipitated which are recrystallisedonce from ethanol and are dried at 100° C in a high vacuum. This gives0.85 g of the compound of the formula ##STR8##

in the form of colourless crystals; melting point 217°-219° C.

Analysis for C₂₆ H₄₈ N₂ O₂ (molecular weight 420.68): Calculated; C,74.24%; H, 11.50%; N, 6.66%; Found C, 74.05%; H, 11.46%; N 6.75%.

Mass Spectrogram: molecule peak 420; fragment masses 41, 337, 295, 236and 154.

Example 2

(a) 3,12-Dimethyl-1,2-diaza-1,5,9-cyclododecatriene ##STR9##

22 g (85 mmols) of nickel acetylacetonate and 22 g (84 mmols) oftriphenylphosphine are dissolved in 2 l of absolute toluene. Approx. 40g (0.74 mol) of 1,3-butadiene are introduced into the green, cleartoluene solution at room temperature (20°-25° C). Reduction is thencarried out at room temperature by means of 35 ml (220 mmols) ofethoxydiethylaluminium, the colour of the solution changing from greento orange-red. The mixture is now warmed as rapidly as possible to 80° Cwhile passing in a steady stream of 1,3-butadiene; 725 g (8.63 mols) ofdiethylidene-hydrazine (acetaldazine) are then added dropwise in such away that a slight excess of 1,3-butadiene is always present. After thefirst addition of diethylidenehydrazine, the colour of the reactionsolution changes to brown and an exothermic reaction sets in; in thecourse thereof, suitable cooling is applied to ensure that thetemperature does not rise above 95° C. After an addition time of 2hours, the mixture is stirred for a further 1 hour at 90°-92° C whilecontinuing to pass in a moderate stream of 1,3-butadiene. After cooling,the catalyst is deactivated with 100 ml of triphenylphosphite. Thetoluene and any by-products which may have been formed are distilled offunder a slight waterpump vacuum (20-30 mm Hg). The residue isfractionally distilled (40 cm Vigreux column) under a waterpump vacuum.This gives 1,375 g of 3,12-dimethyl-1,2-diaza-1,5,9-cyclododecatriene asa colourless oil; yield: 83% of theory, relative todiethylidenehydrazine reacted (conversion 100%); boiling point 110° C/10mm Hg; n_(D) ²⁰ = 1,4861.

Mass spectrogram: molecule peak 192, fragment masses 177, 82, 67 and 54

H¹ -NMR spectrum (100 MHz) δ [ppm] = 5 (multiplet), 3.5 - 3.8(multiplet) 1.5 - 2.8 (multiplet), 1.2 (doublet) in the ratio of4:2:8:6.

(b) 1,10-Dimethyl-1,10-diaminodecane ##STR10##

290.8 g (1.52 mols) of 3,12-dimethyl-1,2-diaza-1,5,9-cyclododecatrieneare dissolved in 1.8 l of pure tert.-butanol. The reaction solution isthen slowly heated to 140°-150° C in a stirred autoclave (temperatureincrease approx, 30° C per hour), 30 g of rhodium-aluminum oxidecatalyst (5% by weight of Rh) are added and hydrogenation is carried outat this temperature for 14 hours (initial pressure 120 bars). Aftercooling the autoclave to room temperature, the catalyst is filtered offthrough silica gel and rinsed with 90 ml of tert.-butanol. The solventis removed, first in a rotary evaporator at 12 mm Hg and then in a highvacuum at a bath temperature of 60° C. This gives 288 g of a colourless,oily residue. This residue is worked up as described in Example 1b) inorder to characterise it and purify it. This gives 252 g (1.255 mols) ofcolourless 1,10-dimethyl-1,10-diaminodecane; boiling point 73° C/0.1 mmHg; n_(D) ²⁰ = 1.4549.

Gas chromatogram: single signal at 98%.

Analysis for C₁₂ H₂₈ N₂ (molecular weight 200.344): Calculated; C,71.83%; H, 14.09%; N 13.96%; Found: C, 71.75%; H, 14.32%; N, 13.75%.

Mass spectrogram: Molecule peak 200; fragment masses 199, 185, 168, 157,142 and 44.

¹³ -C-NMR spectrum (Shifts in ppm of trimethylsilane; solvent CDCl₃)

    ______________________________________                                         ##STR11##                                                                    47.0 (doublet)       C-2                                                      40.2                 C-3                                                      29.8                                                                                               C-5, C-6                                                 29.6                                                                          26.5                 C-4                                                      24.1 (quartet)       C-1 (CH.sub.3)                                           ______________________________________                                    

For further characterisation, the above 1,10-dimethyl-1,10-diaminodecaneis converted, as described in Example 1, into the correspondingbis-acetyl derivative of the formula ##STR12##

melting point 119° C.

Analysis for C₁₆ H₃₂ N₂ O₂ (molecular weight 284.446): Calculated: C,67.55%; H, 11.36%; N, 9.84%; Found: C, 67.9%; H, 11.5%; N, 9.8%.

EXAMPLE 3 (a) 3,12-Diisopropyl-1,2-diaza-1,5,9-cyclododecatriene##STR13##

If 232 g (2.4 mols) of bis-(2-methylpropylidene)hydrazine(isobutyraldazine) are used in Example 2 a) instead of 725 g (8.63 mols)of diethylidenehydrazine, an otherwise identical procedure gives, aftera refining distillation at 0.03 mm Hg, 426 g of3,12-diisopropyl-1,2-diaza-1,5,9-cyclododecatriene as a colourless oil;boiling point 89°-92° C/0.03 mm Hg; yield 72% of theory relative tobis-(2-methylpropylidene)-hydrazine reacted (100% conversion).

Mass spectrogram: molecule peak 248, fragment masses 205, 110 and 95.

Analysis for C₁₆ H₂₈ N₂ (molecular weight 248.41): Calculated; C,77.36%; H, 11.36%; N 11.28%; Found: C,77.26%; H, 11.57%; N, 11.24%.

(b) 1,10-Diisopropyl-1,10-diaminodecane ##STR14##

250 g (1 mol) of 3,12-diisopropyl-1,2-diaza-1,5,9-cyclododecatriene aredissolved in 1.5 l of pure tert.-butanol in a stirred autoclave. Thereaction solution is slowly heated to 140°-150° C, 25 g of arhodium-aluminium oxide catalyst (5% by weight of Rh) are added andhydrogenation is carried out at this temperature for 14 hours (initialpressure 120 bars).

After cooling the autoclave to 20°-25° C, the catalyst is filtered offthrough kieselguhr and rinsed with 130 ml of tert.-butanol. The solventis removed, first in a rotary evaporator at 12 mm Hg and subsequently ina high vacuum at a bath temperature of 60° C. This gives 264 g of acolourless, oily residue.

High-vacuum distillation of this residue through a short Vigreux columngives 8 g of fore-runnings followed by 238 g (0.92 mol) of colourless1,10-diisopropyl-1,10-diaminodecane; boiling point 106°-109° C/0.01 mmHg; n_(D) ²⁰ = 1.4600.

Yield: 92% of theory, relative to3,12-diisopropyl-1,2-diaza-1,5,9-cyclododecatriene reacted.

Gas chromatogram: signal at 96.8% and 2% (mixture of diastereomers).

Analysis for C₁₆ H₃₆ N₂ (molecular weight 256.47): Calculated: C,74.92%; H, 14.15%; N, 10.92%; Found: C, 74.77%; H; 14.34%; N, 10.71%.

Mass spectrogram: molecule peak 256; fragment masses 238, 213, 196, 142,123, 109, 97, 83, 72, 56 and 44.

H¹ -NMR spectrum (100 Megahertz): δ[ppm] = 0.84 (doublet), 0.88(doublet), 0.99 (singlet), 1.29 (singlet), 1.56 (multiplet) and 2.48(multiplet) in the ratio of 6:6:4:16:2:2.

EXAMPLE 4 (a) 3,3,12,12-Tetramethyl-1,2-diaza-1,5,9-cyclododecatriene##STR15##

If 602 g (5.37 mols) of acetone-azine are used in Example 2 (a) insteadof 725 g (8.63 mols) of diethylidenehydrazine, an otherwise identicalprocedure gives, after the refining distillation at 0.02 mm Hg, 1,103 gof 3,3,12,12-tetramethyl-1,2-diaza-1,5,9-cyclododecatriene (boilingpoint 63°-5° C/0.02 mm Hg) as a colourless oil; yield 93.2% of theory,relative to acetone-azine reacted (100% conversion).

Mass spectrogram: molecule peak 220; fragment masses 205, 192, 96 and81.

H¹ -NMR spectrum (100 MHz): δ[ppm] = 4.95 (multiplet), 2.35 - 2.50(multiplet), 1.90 - 2.10 (multiplet) and 1.15 (singlet) in the ratio of4:4:4:12.

(b) 1,1,10,10-Tetramethyl-1,10-diaminodecane ##STR16##

660 g (3 mols) of3,3,12,12-tetramethyl-1,2-diaza-1,5,9-cyclododecatriene are dissolved in4 l of anhydrous (pure) ethylene glycol monomethyl ether in a stirredautoclave and are hydrogenated, with the addition of 30 g ofpalladium-on-charcoal catalyst (5% by weight of Pd), first at 20°-25° Cfor 30 minutes and then at 110°-120° C for 8 hours. After the autoclavehas been cooled to room temperature, the catalyst is filtered offthrough silica gel and rinsed with 100 ml of ethylene glycol monomethylether.

200 ml of cold water are added to the resulting clear reaction solution,whereupon the 3,3,12,12-tetramethyl-1,2-diazacyclododecane of theformula ##STR17## is precipitated in the form of colourless crystals.This product is filtered off, washed twice with a little cold methanoland then dried for 6 hours over P₂ O₅ in a high vacuum; melting point50°-54° C.

Yield: 617 g = 91% of theory, relative to3,3,12,12-tetramethyl-1,2-diaza-1,5,9-cyclododecatriene reacted.

Analysis for C₁₄ H₃₀ N₂ (molecular weight 226.4): Calculated: C, 74.24%;H, 13.36%; N, 12.38%; Found: C, 74.10%, H, 13.39%; N, 12.50%.

Mass spectrogram: molecule peak 226; fragment masses 211, 113, 73 and55.

565 g (2.5 mols) of the above3,3,12,12-tetramethyl-1,2-diazacyclododecane are dissolved in 2.8 l ofpure tert.-butanol and are treated, in a stirred autoclave, with 380 gof ammonia and 110 g of Raney nickel. The reaction mixture is slowlyheated to 230° C (initial pressure 120 bars) and is hydrogenated at thistemperature for 16 hours.

The autoclave is then cooled to 20°-25° C and the catalyst is filteredoff through silica gel and rinsed with 130 ml of tert.-butanol. Thesolvent is removed, first in a rotary evaporator at 12 mm Hg and then ina high vacuum at a bath temperature of 60° C. This gives 555 g of acolourless, oily residue. Subsequent high-vacuum distillation of thisresidue gives 78 g of fore-runnings, consisting of2,11-dimethyldodecane; boiling oint 76°-80° C/0.01 mm Hg; mass spectrum:molecule peak 198, fragment masses at 183, 155, 57 and 43, and, as themain fraction, 452 g of 1,1,10,10-tetramethyl-1,10-diaminodecane;boiling point 93° C/0.01 mm Hg; n_(D) ²⁰ = 1.453. Yield:81% of theory,relative to 3,3,12,12-tetramethyl-1,2-diazacyclododecane reacted.

Gas chromatogram: signal at 98.2% and 1.2% (mixture of diastereomers).

If the purification of the end product is carried out via thebis-hydrochloride as indicated in Example 1(b), a product is obtainedwhich is 99% pure according to gas chromatography.

Analysis for C₁₄ H₃₂ N₂ (molecular weight 228.41): Calculated: C,73,58%; H, 14.12%; N, 12.25%; Found: C, 73.24%; H, 14.28%; N, 12.06%.

Mass spectrogram: molecule peak (M+1) 229; fragment masses: 213, 196 and58.

H¹ -NMR spectrum: (100 MHz) + D₂ O. δ [ppm] = 1.07 (multiplet) and 1.29(singlet) in the ratio 12:16.

For further characterisation, the above1,1,10,10-tetramethyl-1,10-diaminodecane is converted as described inExample 1 into the corresponding bis-acetyl derivative of the formula##STR18## melting point 147°-148° C.

Analysis for C₁₈ H₃₆ N₂ O₂ (molecular weight 312.478): Calculated: C,69.20%; H, 11.61%; N, 8.96%; Found: C, 69.30%; H, 11.67%; N, 8.92%.

H¹ -NMR spectrum (100 MHz): δ [ppm] = 5.5 (multiplet), 1.90 (singlet),1.29 (singlet) and 1.6 (multiplet) in the ratio of 2:6:28:4.

EXAMPLE 5

(a) 3,12-Diethyl-3,12-dimethyl-1,2-diaza-1,5,9-cyclododecatriene##STR19##

2.56 g (10 mmols) of nickel acetylacetonate and 2.6 g (10 mmols) oftriphenylphosphine are dissolved in 50 ml of absolute toluene and thesolution is saturated with butadiene at room temperature. Reduction isthen carried out at room temperature using 3.9 ml (25 mmols) ofethoxydiethyl-aluminum, the catalyst solution thus obtained is warmed to85°-95° C while passing in butadiene continuously and 173 g (1.24 mols)of 2-butylidenehydrazine (2-butanone-azine) are added dropwise at thistemperature in such a way that there is always a slight excess ofbutadiene. After an addition time of 30 minutes, stirring is continuedfor a further 30 minutes at 90° C, the reaction solution is allowed tocool and the catalyst is deactivated by adding 0.5-1 g of sulfur.

The toluene and any volatile by-products which may have been formed andstripped off under a waterpump vacuum and the residue is fractionated at0.4 mm Hg. This gives 167 g (55%) of3,12-diethyl-3,12-dimethyl-1,2-diaza-1,5,9-cyclododecatriene (mixture ofdiastereomers) as a colourless oil, boiling point 103°-4° C/0.4 mm Hg;n_(D) ²⁰ = 1.4895.

Analysis: C₁₆ H₂₈ N₂ (248.41); Calculated: C, 77.36; H, 11.36; N, 11.28;Found: C, 77.63; H, 11.54; N, 11.16;

100 MHz Proton magnetic resonance spectrum (CDCl₃): δ[ppm] 0.8 (f); 1.0(s); 1.1 (s); 1.4-2.8 (m) and 4.8-5.1 (m) in the ratio of 6:3:3:12:4.

(b) 1,10-Diethyl-1,10-dimethyl-1,10-diaminodecane

124 g (0.5 mol) of3,12-diethyl-3,12-dimethyl-1,2-diaza-1,5,9-cyclododecatriene arehydrogenated, in 620 ml of cyclohexane in a stirred autoclave and withthe addition of 12 g of palladium-on-charcoal catalyst (5% by weight ofPd), first at room temperature for 90 minutes and then at 100°-110° Cfor 60 minutes. After filtering off the catalyst and stripping off thesolvent on a rotary evaporator, 123 g (97%) of3,12-diethyl-3,12-dimethyl-1,2-diazacyclododecane (mixture ofdiastereomers) are produced as a yellowish oil.

23 g (90 mmols) of the above3,12-diethyl-3,12-dimethyl-1,2-diazacyclododecane are hydrogenated, in200 ml of cyclohexane in a stirred autoclave and with the addition of 3g of rhodium-aluminum oxide catalyst (5% by weight of Rh), for 17 hoursat 200° C. After filtering off the catalyst and stripping off thesolvent on a rotary evaporator, the residue is fractionated at 0.2 mmHg. This gives 7.7 g (30%) of1,10-diethyl-1,10-dimethyl-1,10-diaminodecane as a colorless oil,boiling point 118°-22° C/0.2 mm Hg, n_(D) ²⁰ = 1.4597.

Analysis C₁₆ H₃₆ N₂ (256.48); Calculated: C, 74.93; H, 14.15; N, 10.92;Found: C, 75.08; H, 14.18; N, 11.00.

100 MHz Proton magnetic resonance spectrum (C₆ O₆); δ[ppm] 0.66 (s);0.84 (f); 0.94 (s) and 1.1-1.5 (m) in the ratio of 4:6:6:20.

EXAMPLE 6 (a) 3,12-Dicyclooctyl-1,2-diaza-1,5,9-cyclododecatriene##STR20##

1.25 g (5 mmols) of nickel acetylacetonate and 1.25 g (5 mmols) oftriphenylphosphine are dissolved in 75 ml of absolute toluene in anampoule and 20 g of butadiene are co-condensed. Reduction is thencarried out at room temperature using 1.8 ml (12 mmols) ofethoxydiethyl-aluminum, 13.8 g (50 mmols) of cyclooctylcarbaldazine areadded to the catalyst solution obtained in this way and the mixture isstirred for 62 hours at room temperature. The catalyst is thendeactivated, the reaction solution is diluted with 200 ml of toluene andfiltered through silica gel and the solvent is stripped off on a rotaryevaporator. Crystallisation of the residue from ethanol gives 6.3 g (33%of 3,12-dicyclooctyl-1,2-diaza-1,5,9-cyclododecatriene. Melting point62°-63° C.

Analysis: C₂₆ H₄₄ N₂ (384.65): Calculated: C, 81.19; H, 11.53; N, 7.28;Found: C, 81.30; H, 11.59; N, 7.48.

100 MHz Proton magnetic resonance spectrum (CDCl₃) δ[ppm] 1.1-2.9(multiplet); 3.03 (doublets)l 3.14 (doublets); 4.8-5.1 (multiplet) inthe ratio of 38:1:1:4.

(b) 1,10-Dicyclooctyl-1,10-diaminodecane

2.5 g (6.5 mmols) of 3,12-dicyclooctyl-1,2-diaza-1,5,9-cyclododecatrieneare hydrogenated, in 100 ml of cyclohexane in a stirred autoclave andwith the addition of 0.6 g of rhodium-aluminum oxide (5% by weight ofrhodium), first at room temperature for 90 minutes and then at 210°-220°C for 6 hours. After filtering off the catalyst and stripping off thesolvent on a rotary evaporator, 2.4 g of crude1,10-dicyclooctyl-1,10-diaminodecane are produced.

For isolation and characteristics, the above diamine is converted intothe corresponding bis-acetyl derivative and the latter is recrystallisedfrom ether/acetonitrile. This gives 0.85 g (27%) ofN,N'-bisacetyl-(1,10-dicyclooctyl-1,10-diaminodecane), melting point144°-9° C.

Analysis C₃₀ H₅₆ N₂ O₂ (476.79): Calculated C, 75.57; H, 11.84; N, 5.87;O, 6.71; Found: C, 75.34; H, 12.03; N, 5.84; O, 7.09.

100 MHz Proton magnetic resonance spectrum (CDCl₃): δ[ppm] 1.0-1.8(multiplet); 1.98 (singlet); 3.76 (multiplet); and 5.6 (doublet) in theratio of 46:6:2:2.

EXAMPLE 7 (a) 3,12-Diheptyl-1,2-diaza-1,5,9-cyclododecatriene ##STR21##

If 37.9 g (0.15 mol) of caprylaldazine are used in Example 5 (a) insteadof 173 g (1.24 mols) of 2-butylidenehydrazine under otherwise identicalreaction conditions and if the mixture is worked up as in Example 6a,8.9 g (16%) of 3,12-diheptyl-1,2-diaza-1,5,9-cyclododecatriene areobtained, melting oint 60°-61° C.

Analysis C₂₄ H₄₄ N₂ (360.63): Calculated: C, 79.93; H, 12.30; N, 7.77;Found: C, 79.95; H, 12.56; N, 8.09.

100 MHz Proton magnetic resonance spectrum (CDCl₃): δ[ppm] 0.84(triplet); 1.23 (multiplet); 1.5-2.0 (multiplet); 2.0-2.9 (multiplet);3.28 (multiplet) and 5.0 (multiplet) in the ratio of 6:20:8:4:2:4.

(b) 2,10-Diheptyl-2,10-diaminodecane

If 3.6 g (10 mmols) of 3,12-diheptyl-1,2-diaza-1,5,9-cyclododecatrieneare used in Example 6b instead of 2.5 g (6.5 mmols) of3,12-dicyclooctyl-1,2-diaza-1,5,9-cyclododecatriene under otherwiseidentical reaction conditions, working up in an analogous manner gives3.5 g of crude 2,10-diheptyl-2,10-diaminodecane as a colourless oil.

For isolation and characterisation, the above diamine is converted intothe corresponding bis-acetyl derivative and the latter is recrystallizedfrom n-propanol. This gives 1.4 g (31%) ofN,N'-bisacetyl-(1,10-diheptyl-1,10-diaminodecane), melting point158°-62° C.

Analysis C₂₈ H₅₆ N₂ O₂ (452.77): Calculated: C, 74.28; H, 12.47; N,6.19; O, 7.07; Found: C, 74.29; H, 12.39; N, 6.53; O, 7.29.

The 1,10-diaminodecanes of the formula I are valuable curing agents forepoxide resins. Products and materials cured by means of them aredistinguished by good thermal and dielectric properties, but, above all,by improved mechanical properties, such as good impact resistance andhigh shear strength under tension as well as good adhesion.

Curable mixtures according to the invention which contain a polyepoxideand, as the curing agent, at least one compound of the formula I, aresuitable, in particular, for the manufacture of mouldings, impregnatedmaterials, coatings, lacquers and sealings.

It is appropriate to use 0.5 to 1.3 equivalents, preferably approx. 1.0equivalent, of active hydrogen atoms, linked to nitrogen, of theparticular 1,10-diaminodecane of the formula I, per 1 equivalent ofepoxide groups of the polyepoxide (a).

Polyepoxides (a) which can be used are above all those which have, onaverage, more than one glycidyl group, β-methylglycidyl group or2,3-epoxycyclopentyl group linked to a hetero atom (for example sulfur,but preferably oxygen or nitrogen); special mention should be made ofbis-(2,3-epoxycyclopentyl) ether; diglycidyl or polyglycidyl ethers ofpolyhydric aliphatic alcohols, such as 1,4-butanediol, or polyalkyleneglycols, such as polypropylene glycols; diglycidyl or polyglycidylethers of cycloaliphatic polyols, such as2,2-bis-(4-hydroxycyclohexyl)-propane; diglycidyl or polyglycidy ethersof polyhydric phenols, such as resorcinol,bis-(p-hydroxyphenyl)-methane, 2,2-bis-(p-hydroxyphenyl)-propane (=Diomethan), 2,2-bis-(4'-hydroxy-3',5'-dibromophenyl)-propane or1,1,2,2-tetrakis-(p-hydroxyphenyl)-ethane, or of condensation productsof phenols and formaldehyde which are obtained under acid conditions,such as phenol novolacs and cresol novolacs; di- orpoly-(β-methylglycidyl) ethers of the abovementioned polyhydric alcoholsor polyhydric phenols; polyglycidyl esters of polybasic carboxylicacids, such as phthalic acid, terephthalic acid, Δ⁴ -tetrahydrophthalicacid and hexahydrophthalic acid; N-glycidyl derivatives of amines,amides and heterocyclic nitrogen bases, such as N,N-diglycidyl aniline,N,N-diglycidyltoluidine andN,N,N',N'-tetraglycidyl-bis-(p-aminophenyl)-methane; triglycidylisocyanurate; N,N'-diglycidyl ethyleneurea;N,N'-diglycidyl-5,5-dimethylhydantoin,N,N'-diglycidyl-5-isopropylhydantoin andN,N'-diglycidyl-5,5-dimethyl-6-isopropyl-5,6-dihydrouracil.

If desired, the viscosity of the polyepoxides can be reduced by addingactive diluents, such as styrene oxide, butyl glycidyl ether, isooctylglycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether andglycidyl esters of synthetic, highly branched aliphatic monocarboxylicacids which are mainly tertiary.

The curable mixtures according to the invention are appropriately curedto give moulded articles and the like within the temperature range from20° to 160° C. The curing can also be carried out in a known manner intwo or more stages, the first curing stage being carried out at a lowertemperature and the post-curing at a higher temperature.

If desired, the curing can also be carried out in 2 stages in such a waythat the curing reaction is first discontinued prematurely or the firststage is carried out at room temperature (20°-25° C) or at an onlyslightly elevated temperature, a curable procondensate which is stillfusible and/or soluble (so-called "B stage") being obtained from theepoxide component (a) and the curing agent (b). A precondensate of thiskind can be used, for example, for the manufacture of "prepregs",compression moulding compositions or, in particular, sintering powders.

In order to shorten the gelling or curing times, it is possible to addaccelerators which are known for amine curing, for example monphenols orpolyphenols, such as phenol or Diomethan, salicylic acid, tertiaryamines or salts of thiocyanic acid, such as NH₄ SCN.

The expression "cure", as used here, denotes the conversion of thesoluble, either liquid or fusible polyepoxides into solid, insoluble andinfusible products or materials which are crosslinked in threedimensions, and, as a rule, with simultaneous shaping to form shapedarticles, such as cast articles, moulded articles and laminates, and toform impregnated materials, coatings, lacquer films or sealings.

The curable mixtures according to the invention formed from polyepoxides(a) and 1,10-diaminodecanes of the formula I as the curing agent canalso be treated, before curing, in any phase with customary modifyingagents, such as extenders, fillers and reinforcing agents, pigments,dyestuffs, organic solvents, plasticisers, flow control agents,thixotropic agents, flame-retarding materials and mould release agents.

The following examples should be mentioned as extenders, reinforcingagents, fillers and pigments which can be employed in the curablemixtures according to the invention: coal tar, bitumen, textile fibers,glass fibers, asbestos fibers, boron fibers, carbon fibers, cellulose,polyethylene powder and polypropylene powder; quartz powder, mineralsilicates, such as mica, ground asbestos and ground shale; kaolin,aluminum oxide trihydrate, ground chalk, gypsum, antimony trioxide,bentonite, silicic acid aerogel, lithopone, barite, titanium dioxide,carbon black, graphite, oxide colorants, such as iron oxide, or metalpowders, such as aluminum powder or iron powder.

Examples of organic solvents which are suitable for modifying thecurable mixtures are toluene, xylene, n-propanol, butyl acetate,acetone, methyl ethyl ketone, diacetone alcohol and ethylene glycolmonomethyl, monoethyl and monobutyl ethers.

Examples of plasticizers which can be employed for modifying the curablemixtures are dibutyl, dioctyl and dinonyl phthalates, tricresylphosphate, trixylenyl phosphate and also polypropylene glycols.

Examples of flow control agents which can be added when using thecurable mixtures, particularly in protecting surfaces, are silicones,cellulose acetobutyrate, polyvinylbutyral, waxes, stearates and the like(which can, in part, also be used as mould release agents).

Especially when used in the field of lacquers, it is also possible forthe polyepoxides to be partially esterified in a known manner withcarboxylic acids, such as, in particular, higher unsaturated fattyacids. It is also possible to add other curable synthetic resins, forexample phenoplasts or aminoplasts, to such lacquer resin formulations.

The production of the curable mixtures according to the invention can becarried out in a customary manner with the aid of known mixing units(stirrers, kneaders, rollers and the like).

The curable epoxide resin mixtures according to the invention areemployed above all in the fields of surface protection, the electricalindustry, laminating processes and in the building industry. They can beused in a formulation which is suited in each particular case to thespecial end use, in an unfilled or filled state, if appropriate in theform of solutions or emulsions, as paints or lacquers, as sinteringpowders. compression moulding compositions, injection mouldingformulations, dipping resins, casting resins, impregnating resins,binders and adhesives, and as moulding resins, laminating resins,sealing compositions and primers, flooring compositions and binders formineral aggregates.

The epoxide resin which follows was used for the production of curablemixtures, which is described in the following use examples:

Epoxide resin A

A polyglycidyl ether resin (an industrial product) which is manufacturedby condensation of 2,2-bis-(p-hydroxypheyl)-propane with astoichiometric excess of epichlorohydrin in the presence of alkali, andwhich mainly consists of Diomethan diglycidyl ether of the formula##STR22## and which is liquid at room temperature and has the followingcharacteristics:

Epoxide content: 5.1 - 5.5 epoxide equivalents/kg

Viscosity (Hoeppler) at 25° C: 9000 - 13,000 cP.

B. Use Examples

The following curable mixtures are used:

Example I: 100 g of epoxide resin A and 44.5 g of1,10-dicyclohexyl-1,10-diaminodecane prepared in accordance with Example1.

Example II: 100 g of epoxide resin A and 26.5 g of1,10-dimethyl-1,10-diaminodecane prepared in accordance with Example 2.

Example III: 100 g of epoxide resin A and 30.2 g of1,1,10,10-tetramethyl-1,10-diaminodecane prepared in accordance withExample 4.

Comparison Examples

Example IV: 100 g of epoxide resin A and 12.8 g of triethylenetetramine.

Example V: 100 g of epoxide resin A and 31.5 g of4,4'-methylene-bis-(3-methylcyclohexylamine)[3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane].

Examle VI: 100 g of epoxide resin A and 22.5 g of3-aminomethyl-3,5,5-trimethylcyclohexylamine.

Example VII: 100 g of epoxide resin A and 21 g oftrimethylhexamethylenediamine.

The test specimens are prepared by mixing the diamines with the epoxideresin at room temperature (20°-25° C), briefly degassing the mixture invacuo and then casting it as indicated below to form sheets or films.Curing is carried out first for 24 hours at 40° C and then for 6 hoursat 100° C.

3 mm thick sheets are prepared from the above mixtures in an aluminiummould in order to determine the mechanical properties, that is to saythe flexural strength, the bending angle and the impact flexuralstrength according to Dynstat (compare W. Holzmuller and K. Altenburg,"Physik der Kunststoffe", Akademie-Verlag Berlin, 1961, pages 597-604)and the increase in weight after storage in water.

Sheets 2 mm thick are prepared from the above mixtures in an aluminiummould in order to determine the electrical properties, that is to saythe dielectric loss factor tan δ according to DIN 53,483 (= ASTM D 150),the dielectric constant ε according to DIN 53,483 and the specificvolume resistivity according to DIN 53,482.

Small sheets 1.5 mm thick are cast from the above mixtures on analuminium mould in order to determine the glass transition temperatureon a differential thermoanalysis apparatus (type TA 2000 of Messrs.Mettler, Greifensee, Switzerland).

Films of 50 μ thickness are produced with the above mixtures by means ofa drawing triangle on iron sheets degreased with trichloromethylene andthe impact deep-drawing value, after being struck from behind with ahammer, and the Erichsen deepdrawing values (DIN 53,156) are measured onthese films.

Test strips of Anticorodal B (an aluminium alloy containing magnsium andsilicon of Messrs. Schweizer Aluminium AG; 170 × 25 × 1.5 mm) which havebeen roughened by grinding and cleansed by washing with acetone arecoated at their ends with the above mixtures. The coated ends of twotest strips are in each case placed upon one another in such a way thatthey overlap by 10 mm and are then fixed in this position by a clamp andare cured. The shear strength under tension of the sealing is measuredin accordance with DIN 53,283 on the test specimens thus obtained.

The results are summarised in Table I which follows:

                                      TABLE I                                     __________________________________________________________________________                          Cast specimen according to                                                                       Compari-                                                                           Compari-                                                                 son  0                                                                        Example                                                                            Example                         Properties            Example I                                                                           Example II                                                                          Example III                                                                          IV   V                               __________________________________________________________________________    Impact flexural strength according to                                         Dynstat (cm.kg/cm.sup.2)                                                                            21.0  16.5  27.0   8.3  13.0                            Flexural strength according to Dynstat                                        (kg/mm.sup.2)         1225  1195  1175   1335 1450                            Bending angle according to Dynstat (° C)                                                      53   52    56      49  55                              Glass transition temperature (° C)                                                            110  97    89      113 130                             Water pick-up after storing for 4 days in                                     water at 25° C (%)                                                                            0.20  0.29  0.20   0.26                                                                               0.35                           Water pick-up after storing for 1 hour in                                     boiling water (%)      0.30  0.61  0.40   0.45                                                                               0.36                           Shear strength under tension on Anti-                                         corodal B according to DIN 53,283 (kg/mm.sup.2)                                                     0.9   1.8   1.5    0.4  --                              Appearance of the lacquer film                                                                      High  Matt  High   Slightly                                                   gloss       gloss  cloudy                               Erichsen deep-drawing value according to                                      DIN 53,156 (mm at 20° C)                                                                     7.3   9.3   7.6    4.9  5.4                             Impact deep-drawing value, struck from                                        behind (cm/kg hammer) 40/1  90/2  80/2   30/1 25/1                            Dielectric loss factor according to DIN                                       53,483 tan δ > 1% above                                                                       98°                                                                           94°                                                                         75°                                                                           73°                                                                         120°                     > 5% above            132°                                                                         108°                                                                         90°                                                                           98°                                                                         165°                     Dielectric constant ε at 25° C                                                       3.9   4.1   3.9    4.6  5.0                             Specific volume resistivity at 25° C                                   (ohm . CM)            6.4 × 10.sup.16                                                               4.4 × 10.sup.16                                                               2.4 × 10.sup.16                                                                5 × 10.sup.16                                                                5 × 10.sup.16             DIN = German Industrial Standards                                             __________________________________________________________________________

The reactivity of the 1,10-diaminodecanes according to the invention ascuring agents for epoxide resins is, surprisingly, much lower than wouldbe expected by virtue of the aliphatic character in itself. These newcuring agents therefore represent a technical advance. The difference inreactivity compared with conventional aliphatic amines is illustrated bymeasuring the gel time and operating time and by means of differentialthermo-analysis. The viscosity values also show that the curablemixtures containing the amines according to the invention have a low(that is to say favourable) viscosity.

Differential thermo-analysis

˜20 mg of the resin:curing agent mixture to be tested are weighed into asmall Al crucible and the crucible is closed and placed on the measuringsensor in the oven of a differential thermo-analyser (type TA 2000 ofMessrs. Mettler, Griefensee, Switzerland). The sample is warmed at aheating rate of 4° C/minute and the reaction is followed by measuringthe temperature difference between a full and an empty crucible. Thetemperature at the start of the reaction, the temperature at the maximumreaction rate and the temperature at the end of the reaction are readoff from the curve which is produced and the heat liberated during thereaction is determined by measuring the area below the curve.

Measurement of operating time

The change in viscosity with time is determined under isothermalconditions in a Hoeppler falling ball viscosimeter at 25° and at 40° Con another portion of the resin-curing agent mixture and the timerequired to reach 1,500, 3,000 and 10,000 cP is recorded.

Measurement of gel time

Finally. the gel time is determined on another sample of theresin-curing agent mixture at 80°, 100° and 120° C on athermostatically-controlled hotplate.

The values obtained are summarised in Table Ia.

                                      Table Ia                                    __________________________________________________________________________    Example              I     II    III   IV    V     VI    VII                  __________________________________________________________________________    Initial viscosity at 25° C (cP)                                                                   525         2,500 2,200 3,400 800                  Operating time at 25° C                                                 up to 1,000 cP [minutes]                                                                          --    139   --    --    --    --    26                    up to 3,000 cP      --    269   --     5    --    --    53                    up to 10,000 cP     --    303   --    40    120   60    90                   Operating time at 40° C                                                 up to 1,500 cP [minutes]                                                                          --     91   --    12     48   24    25                    up to 3,000 cP      --    108   --    18     60   33    30                    up to 10,000 cP     --    139   --    30    150   42    40                   Gel time at  80° C                                                                          --    30'   --    7'40" 27'   12'   11'30"               100° C        --    10'50"                                                                              --    2'20" 13'15"                                                                               8'50"                                                                               4'30"               120° C        --     5'   --    1'10"  6'30"                                                                               4'30"                                                                               1'                  Path of Start of reaction (° C)                                                              48    36    49   32     37   35    33                   curve in                                                                              Maximum of reaction (° C                                                            118   104   117   81    105   93    90                   differential                                                                          End of reaction (° C)                                                               248   195   245   162   199   197   206                  thermo-analysis                                                                       Enthalpy Cal/equivalent                                                                    21,670                                                                              24,345                                                                              20,145                                                                              22,580                                                                              21,960                                                                              21,440                                                                              24,200               __________________________________________________________________________                                                             f                

Films 50μ thick are prepared as described above on degreased iron sheetsusing the curable mixture II, the following curing conditions beingused:

1 day at 20° C,

1 week at 20° C,

1 month at 20° C,

2 months at 20° C and

2 months at 60° C.

The following investigations relating to lacquer technology are thencarried out.

Gel time using Tecam apparatus, 100 cm³ in Al can, 20° C Time until dryto permit handling and complete curing time using Landolt apparatus, Δ200 μm 65% relative humidity Flow, transparency, surface aspect andexudation, visual assessment

Hardness by Persoz method, Δ 200 μm, 20° C 65% relative humidity

Erichsen deep-drawing value, Δ 200 μm, 20° C, 65% relative humidity, DIN58,156

Impact test, Δ200 μm, 20° C 65% relative humidity, impact on coating

Mandrel bending test, Δ 200 μm, 20° C 65% relative humidity

Boiling water test, application by brush to sandblasted steel sheet,visual assessment, curing for 10 days at room temperature.

Adhesion, application by brush to sandblasted steel sheet, visualassessment, curing for 10 days at room temperature.

The results are summarised in Table II which follows:

                  Table II                                                        ______________________________________                                        Test                    Test value                                            ______________________________________                                        Gel time hours           91/2                                                 Time until dry to permit                                                                              15                                                    handling (hours)                                                              Complete curing time hours                                                                            18                                                    Exudation               None                                                  Hardness by Persoz method                                                     1 day 20° C seconds                                                                            100                                                   1 week 20° C seconds                                                                           200                                                   1 month 20° C seconds                                                                          200                                                   Erichsen test DIN 53,156                                                      2 months 20° C μm                                                                           0.5                                                   2 months 60° C μm                                                                           1-3                                                   Impact test                                                                   2 months 20° C cm.kg                                                                           10                                                    2 months 60° C cm.kg                                                                           40                                                    Mandrel bending test, 15 mm mandrel                                           2 months 20° C   10° (angle)                                    2 months 60° C   60° (angle)                                    ______________________________________                                    

What we claim is:
 1. Curable mixtures which are suitable for themanufacture of mouldings, impregnated materials, coatings, lacquers andsealings, characterised in that they contain (a) a compound having morethan one epoxy group and (b), as the curing agent, at least one1,10-diaminodecane of the formula I ##STR23## wherein R₁ and R₃independently of one another represent an alkyl, cycloalkyl, aralkyl,phenyl or naphthyl group and R₂ and R₄ independently of one anotherrepresent hydrogen, alkyl, cycloalkyl, aralkyl, phenyl or naphthyl groupor R₁ and R₂ and/or R₃ and R₄, conjointly with the carbon atom to whichthey are linked, form a 5-membered to 12-membered alkylene oroxaalkylene ring.
 2. Mixtures according to claim 1, characterised inthat they contain 0.5 to 1.3, preferably approx. 1.0, equivalent ofactive hydrogen atoms, linked to nitrogen, of the particular1,10-diaminodecane (b), per 1 equivalent of epoxide groups of thepolyepoxide (a).
 3. Mixtures according to claim 1, characterised in thatthey contain, as the curing agent (b), at least one 1,10-diaminodecaneof the formula I wherein R₁ and R₃ independently of one another denotean unsubstituted alkyl group having 1-18, particularly 1-8, carbonatoms, a 1-nuclear or 2-nuclear cycloalkyl group having 5-10 ring carbonatoms, which can be substituted by alkoxy, alkylamino orN,N-dialkylamino groups having in each case 1 or 2 carbon atoms in thealkoxy or alkyl portions, the benzyl or 2-phenylethyl group, anunsubstituted phenyl group or a phenyl group which is substituted byalkyl, alkoxy, alkylamino or N,N-dialkylamino groups having in each case1 or 2 carbon atoms in the alkyl or alkoxy portions, or an unsubstitutednaphthyl group, and R₂ and R₄ independently of one another denotehydrogen or a group corresponding to R₁ or R₃.
 4. Mixtures according toclaim 1, characterised in that they contain, as the curing agent (b), atleast one 1,10-diaminodecane of the formula I wherein R₁ and R₂ and/orR₃ and R₄, conjointly with the carbon atom to which they are linked forman unsubstituted 5-membered to 12-membered alkylene ring or anunsubstituted 5-membered or 6-membered oxaalkylene ring.
 5. Mixturesaccording to claim 1, characterised in that they contain, as the curingagent (b), at least one 1,10-diaminodecane of the formula I wherein R₁and R₃ as well as R₂ and R₄ have, in each relevant case, the samemeaning.
 6. Mixtures according to claim 1, characterised in that theycontain, as the curing agent (b), at least one 1,10-diaminodecane of theformula I, wherein R₁ and R₃ each represent an unsubstituted alkyl grouphaving 1-8 carbon atoms or a 1-nuclear or 2-nuclear cycloalkyl groupwhich has 5-10 ring carbon atoms and is unsubstituted or substituted byalkoxy, alkylamino or N,N-dialkylamino groups having in each case 1 or 2carbon atoms in the alkoxy or alkyl portions, and R₂ and R₄ eachrepresent hydrogen or an unsubstituted alkyl group having 1-8 carbonatoms.
 7. Mixtures according to claim 6, characterised in that theycontain, as the curing agent (b), at least one 1,10-diaminodecane of theformula I wherein R₁ and R₃ are identical and represent an unsubstitutedalkyl group having 1 to 8 carbon atoms or a 1-nuclear cycloalkyl grouphaving 6 to 8 ring carbon atoms, and wherein R₂ and R₄ are different anddenote hydrogen or an unsubstituted alkyl group having 1 to 8 carbonatoms, preferably methyl or ethyl.
 8. A 1,10-Diaminodecane of theformula Ia ##STR24## wherein R₁, R₂, R'₃ and R₄ are identical, andrepresent alkyl, cycloalkyl, aralkyl, phenyl, naphthyl, or R₁ and R₂and/or R₃ and R₄ conjointly with the carbon atom to which they arelinked, form a 5-membered to 12-membered alkylene or oxaalkylene ring.9. 1,10-Diaminodecanes of the formula Ia according to claim 8, whereinR₁ and R₂ and/or R₃ ' and R₄, conjointly with the carbon atom to whichthey are linked, form an unsubstituted 5-membered to 12-memberedalkylene ring or an unsubstituted 5-membered or 6-membered oxaalkylenering.
 10. The compound 1,10-diethyl-1,10-dimethyl-1,10-diaminodecane.11. Process for the manufacture of 1,10-diaminodecanes of the formula Ia##STR25## wherein R₁ represents an alkyl, cycloalkyl, aralkyl, phenyl ornaphthyl group, R₃ ' represents an alkyl, cycloalkyl, aralkyl ornaphthyl group which corresponds to R₃, or represents a phenyl group andR₂ and R₄ independently of one another represent hydrogen or an alkyl,cycloalkyl, aralkyl, phenyl or naphthyl group, or R₁ and R₂ and/or R₃ 'and R₄, conjointly with the carbon atom to which they are linked, form a5-membered to 12-membered alkylene or oxaalkylene ring, characterised inthat a compound of the formula ##STR26## wherein what has been indicatedunder formula Ia applies to R₁, R₂, R₃ ' and R₄, is hydrogenated in thepresence of an inert organic solvent, by catalytic means, in one or twostages and with the reaction temperature being raised to at least 120°C, to give a compound of the formula Ia.
 12. Process according to claim11, characterised in that, in a first stage, a compound of the formulaII is hydrogenated at a temperature below 150° C to give a compound ofthe formula III ##STR27## and the compound of the formula III is thenhydrogenated at elevated temperature and preferably with the addition ofammonia, to give a compound of the formula Ia.
 13. Process according toclaim 11, for the manufacture of 1,10-diaminodecanes of the formula I,wherein R₂ and R₄ each represent hydrogen, characterised in that acompound of the formula II, wherein R₂ and R₄ each denote hydrogen andwhat has been indicated under formula Ia applies to R₁ and R₃ ', ishydrogenated in one stage at a temperature of at least 120° C. 14.Process according to claim 11, characterised in that the compound of theformula II which is employed is one in which R₁ and R'₃ are identicaland represent an alkyl group having 1 to 8 carbon atoms or a 1-nuclearcycloalkyl group having 6 to 8 ring carbon atoms, and wherein R₂ and R₄are different and denote hydrogen or an alkyl group having 1 to 8 carbonatoms, preferably methyl or ethyl.